Sagittal view of left face at the pterygopalatine fossa. Mucosa of the nasopharynx and the perpendicular plate of the palatine bone have been removed to visualize the pterygopalatine fossa. The maxillary nerve (CN V2) enters this fossa via the foramen rotundum. Here, pterygopalatine branches connect the maxillary nerve with the pterygopalatine ganglion. The nerve of the pterygoid canal (Vidian nerve) also enters this fossa. It contains preganglionic parasympathetic fibers that synapse on the postganglionic parasympathetic neurons in the pterygopalatine ganglion. Postganglionic fibers are distributed along branches of the maxillary nerve to supply the lacrimal glands and small glands of the nasal and oral cavities. The largest branch of the maxillary nerve, the infraorbital nerve, courses forward through the inferior orbital fissure to enter a groove on the floor of the orbit in company with the infraorbital artery, a branch of the maxillary artery. The floor of the orbit also serves as the roof of the maxillary sinus (exposed here following removal of the turbinates). The sphenopalatine foramen (located immediately posterior to the middle turbinate) marks the opening of the pterygopalatine fossa with the nasal cavity. Removal of the perpendicular plate of the palatine bone provides greater exposure of this fossa and contents of the greater palatine canal. The sphenopalatine artery, a terminal branch of the maxillary artery, gives rise to the pharyngeal artery and artery of the pterygoid canal as well as branches to the lateral nasal wall and septum. The descending palatine artery divides into the lesser and greater palatine arteries that pass through corresponding foramina to supply the soft and hard palate, respectively. Palatine nerves similarly give rise to greater and lesser palatine nerves to the palate. The lateral wall of the nasopharynx shows the torus tubarius and opening of the Eustachian (pharyngotympanic) tube as well as the tensor veli palatini muscle descending lateral to the medial pterygoid plate (exposed). Its tendon wraps around the hamulus of this plate to enter the soft palate. Its attachment to the tube also allows the muscle to open the tube during swallowing. Below the hard palate (cut) is the tongue. Posterior to the tongue is the oropharynx. Above the plane of the soft palate (cut) is the nasopharynx. The lateral wall of the sphenoid body (containing the sphenoid sinus) has been removed to reveal the internal carotid artery. Superiorly, the body presents the sella turcica for the pituitary gland. (Image courtesy of AL Rhoton, Jr.)